I own the Hooked on Phonics K-2nd grade kits and I just got the Ordinary Parent's Guide from the library. I've lined them up and done a little comparison, trying to see where we are and if it's worth it.
At this point, I think it will be once we finish HOP 2nd grade.
We have now completed K and 1st grade and while it doesn't line up completely (the scope and sequences are different) it look like we've worked through section 7- out of 25 available sections. The next kit will get us further- how much I don't entirely know since I'm not familiar with all the word lists yet, but it won't get us through the end of the book. I believe that I've seen around that the Ordinary Parent's Guide goes through about a 4th grade level and looking at it that seems about right. It's also very reasonable.
So far I've had the following learn to read programs- Teach your Child to Read in 100 Easy Lessons, Hooked on Phonics, McGuffey's, and now I'm borrowing the Ordinary Parent's Guide.
My current favorites would be the Hooked on Phonics, the the Ordinary Parent's Guide, the McGuffey's.
I completely dislike the 100 easy lessons. I'm not getting rid of it, I'll keep it in case it meshes with the learning style of a later child, but it's way too scripted and I strongly dislike the annotated alphabet. I think that it could be an awful transition once you drop the marks, and beginning it with a child that knew the letter sounds introducing the marks was unpleasant, as well.
I'd like the McGuffey's better if it had more phonetical instruction. I think it's more of what we now call incidental phonics- but I could be confusing that. They are currently mostly useful to us as readers and extra practice.